The present invention relates to avoidance and treatment of irritation resulting from friction or pressure against an area of skin.
It is well known that poorly fitting shoes, gloves, and other clothing can rub a person's skin and thereby cause significant irritation, soreness, or blisters, or may rub away a portion of the skin's surface. Such irritation by friction can be caused by straps of undergarments, by the rubbing of casts on the skin thinly covering a joint, such as a person's wrist within such a cast, or by athletic clothing or equipment rubbing a person's skin, as when a person is riding a bicycle or performing other physically demanding exercise over an extended time, particularly when there is pressure against the skin. Soreness may also be caused by friction against the skin of person in a wheelchair or confined to bed for a long time.
Attempts to avoid injury of skin by such friction in the past have included the use of devices intended to slip easily along the surface of the skin, as disclosed in Eilender et al. U.S. Pat. Nos. 4,959,059 and 4,572,174. Approaching the problem in another way, dressings intended to slip easily over adjacent materials are disclosed in Feret U.S. Pat. Nos. 5,012,801 and 5,188,124.
Various other devices have been intended to protect an irritated area of a person's skin by providing a structure supported by adjacent skin to push irritant surfaces away from irritated skin, or to equalize pressure on areas of a person's skin likely to be irritated. Such devices are disclosed in Kaufman U.S. Pat. No. 1,913,928, Scholl U.S. Pat. No. 2,098,312, Spence U.S. Pat. No. 3,548,420, Grubel U.S. Pat. No. 3,821,954, Gallovich U.S. Pat. No. 3,260,261, and Dyson U.S. Pat. No. 3,968,530. An inflatable pad for protecting bedsores is disclosed by Carver U.S. Pat. No. 5,462,519.
The devices disclosed in the patents mentioned above however, have not proved entirely satisfactory, for various reasons. Many of the devices previously known have acted as pads, but have not satisfactorily protected skin against the effects of friction and pressure against an adjacent surface. Such friction causes the skin to be pulled in directions parallel to its surface, generating shear forces within the skin that eventually irritate and cause injury to the skin, despite the use of the previously known devices for protecting the skin. Additionally, the previously known devices, with few exceptions, have had a thickness which of itself increases the pressure of an adjacent surface against skin in many situations, such as where a shoe fits poorly.
Consequently, what is still needed is an improved device for protecting a person's skin from the causes of friction. Preferably such an improved device should be thin, to avoid adding to pressure on the skin, should greatly reduce friction between the skin and an adjacent surface, should be easily and cheaply manufactured, and should be easy to use.